In patent Application IT2012BO00316 an automatic manual transmission for a car provided with an internal combustion engine has been proposed. The automatic manual transmission comprises a mechanical gearbox provided with a primary shaft, a secondary shaft, a plurality of pairs of gears, and a plurality of servo-assisted locking devices activated by first actuators. Moreover, the automatic manual transmission comprises a servo-assisted drive device with a variable gear ratio, which is interposed between a drive shaft originating from the internal combustion engine and the primary shaft and can be adjusted so as to present two different gear ratios: a first even direct drive gear ratio and a second increased gear ratio. Finally, the automatic manual transmission comprises a second actuator, which is coupled to the drive device, so as to vary the gear ratio of the drive device. To change gears, a control unit controls, in a coordinated manner, the first actuators and the second actuator so as to combine a gear ratio of the drive device with a gear ratio of the gearbox to obtain a corresponding gear.
In the automatic manual transmission described in Patent Application IT2012BO00316, there may be a need to mechanically connect an electrical machine to make the car hybrid; to this end, there is a need for the electrical machine to effectively perform different functions in an energetically efficient manner (mainly start the internal combustion engine, generate power when there is a need to recharge the storage system, apply torque to the driving wheels where there is a need for electric traction, and regenerative braking). To this end, it is worth noting that the electrical machine has very precise limitations, that it is not capable of running at all engine speeds (in particular, it may normally run very slowly, but not run very quickly), or of operating in an energetically efficient manner at all engine speeds, or of generating/absorbing high torques at all engine speeds.
Patent Application US2011167956 describes an automatic manual hybrid transmission. In a first embodiment, a single-clutch gearbox is provided and the shaft of the electrical machine is directly connected to the secondary shaft of the gearbox. In a second embodiment, a twin-clutch gearbox is provided, provided with one primary shaft and two secondary shafts and the shaft of the electrical machine can be connected to both the secondary shafts of the gearbox by means of one gear train.